1. Field of the Invention
The present invention is related to autonomic copy services solutions.
2. Description of the Related Art
Disaster recovery systems typically address two types of failures, a sudden catastrophic failure at a single point in time or data loss over a period of time. In the second type of gradual disaster, updates to volumes may be lost. A volume is any logical or physical element of storage. To assist in recovery of data updates, a copy of data may be provided at a remote location. Such dual or shadow copies are typically made as the application system is writing new data to a primary storage device. A storage device is a physical unit that provides a mechanism to store data on a given medium, such that the data can be subsequently retrieved.
International Business Machines Corporation (IBM), the assignee of the subject patent application, provides systems for maintaining remote copies of data at a secondary storage device, including peer-to-peer remote copy (PPRC). The PPRC system provides techniques for recovering data updates between a last, safe backup and a system failure. Such data shadowing systems can also provide an additional remote copy for non-recovery purposes, such as local access at a remote site.
Moreover, a number of direct access storage device (DASD) subsystems are capable of performing “instant virtual copy” operations, also referred to as “fast replicate functions.” Instant virtual copy operations work by modifying metadata such as relationship tables or pointers to treat a source data object as both the original and copy. In response to a host's copy request, the storage subsystem immediately reports creation of the copy without having made any physical copy of the data. Only a “virtual” copy has been created, and the absence of an additional physical copy is completely unknown to the host.
Later, when the storage system receives updates to the original or copy, the updates are stored separately and cross-referenced to the updated data object only. At this point, the original and copy data objects begin to diverge. The initial benefit is that the instant virtual copy occurs almost instantaneously, completing much faster than a normal physical copy operation. This frees the host and storage subsystem to perform other tasks. The host or storage subsystem may even proceed to create an actual, physical copy of the original data object during background processing, or at another time.
Instant virtual copy has been an important development in modern disk subsystems, and a number of different techniques have surfaced. As one example, International Business Machines Corporation (IBM) has developed the FlashCopy® copy services solution, as described in different publications including U.S. application Ser. No. 09/347,344, filed on Jul. 2, 1999 and entitled “Method, System, and Program for Maintaining Electronic Data as of a Point-In-Time.” A different fast replicate technique is the “SNAPSHOT” copy services solution disclosed in U.S. Pat. No. 5,410,667 entitled “Data Record Copy System for a Disk Drive Array Data Storage Subsystem,” which issued on Apr. 25, 1995. The foregoing references are incorporated herein by reference in their entirety.
Instant virtual copy techniques have been developed, at least in part, to quickly create a duplicate copy of data without interrupting or slowing foreground processes. Instant virtual copy techniques, such as a FlashCopy® copy services solution, provide a point-in-time copy tool. Instant virtual copy techniques may be used for a variety of applications, including, for example, data backup, data migration, data mining, testing, etc.
For example, an instant virtual copy technique may be used for the creation of a physical “backup” copy of the source data, to aid in disaster recovery. Under one such technique, a copy services solution, such as a FlashCopy® or “SNAPSHOT” copy services solution, is used to perform an instant virtual copy operation; this creates a virtual target volume identical to the source volume in all respects. Then, the virtual target volume is taken off-line (i.e., is not accessible), which may occur automatically as a result of the instant virtual copy operation or manually at the direction of a system administrator.
There are many different copy services solutions across different vendors, some being similar to each other and some being very different. Many of the copy services solutions, however, are made up of a set of base copy services solutions strung together to create a new copy services solution. FIG. 1 illustrates a prior art copy services solution. This solution performs a FlashCopy® copy services solution from volume A 100 to volume B 102, a Peer to Peer Remote Copy (PPRC) copy services solution from volume B 102 to volume C 104, and a final FlashCopy® copy services solution from volume C 104 to volume D 106 to generate a remote point-in-time copy (i.e., a point-in-time copy at a remote site). Volumes A, B, C, and D may be located at a same physical site or at different physical sites. As another example, a remote point-in-time copy may be generated with a PPRC synchronous copy to a local site, and then a PPRC asynchronous copy to a remote site.
Because different customers have different needs, different copy services solutions are formed to address the needs. However, it is difficult to keep up with the growing number of copy services solutions. Many of these copy services solutions, given hardware alone, require manual intervention, which is inefficient and leads to human error. Also, current copy services solutions involve writing complex management code for specific copy types that run complex scripts, which are difficult to set up. This is a very time consuming and error prone task for a storage administrator.
Therefore, there is a need in the art for improved copy services solutions.